In the past, paint mixers of the gyroscopic and platform types used various clamping mechanisms to secure the paint container in the mixer. Such mechanisms typically required an operator to advance or retract a clamping pad or plate with respect to one end of the paint container or containers held for mixing. Furthermore, to retain the paint container securely, the clamp mechanism requires a lock to prevent unintentional release or slippage of such clamping mechanisms. Such clamping and locking mechanisms often were constructed of a number of parts needing alignment for proper operation, due in part to the separation of functions between the clamping parts and the locking parts, which nevertheless were required to work together. The relatively large number of parts on occasion caused relatively high friction in the mechanism, making it difficult for the operator to use the clamp and lock. Furthermore, the large number of parts added to the cost of manufacture and service.